Lennox CBK47UHET-042-230-01 21.25" Width 42,000 BTU Air Handler

The Lennox CBK47UHET-042-230-01 is a 3.5 ton Elite Series air handler for R-410A systems, with a constant torque (ECM) blower and an R-410A check/expansion valve installed at the factory. It comes in a 21.25-inch wide cabinet that ships ready for upflow or horizontal installs.

Key specs

• Capacity: 3.5 tons (42,000 BTU)
• Blower: 1 hp constant torque motor, 815 to 1,723 cfm
• Connections: 3/8-inch liquid and 7/8-inch suction, sweat, plus two 3/4-inch FPT drains
• Filter: 20 x 24 x 1 inch
• Shipping weight: 186 lb
• Coil: Lennox Quantum coil with aluminum tubing and ripple-edged aluminum fins

Reading the model number

CB is an air handler, K means R-454B compatible, and 47 is the Elite Series with the Quantum coil. UH is upflow/horizontal, E is the high-efficiency constant torque motor, and T is the factory check/expansion valve. 042 is 3.5 tons, 230 is 208/230V single-phase, and 01 means an R-410A valve is installed.

What it pairs with

As shipped, it's set up for R-410A. The air conditioners and heat pumps we sell use R-454B, so pairing it with one needs Lennox's R-454B expansion valve and refrigerant detection parts, ordered separately.

For electric heat, Lennox lists ECB47 heaters from 4 to 25 kW for this size: 4, 5, 6, 8, and 9 kW with a terminal block or a circuit breaker; 12.5, 15, 20, and 25 kW with a circuit breaker. Three-phase ECB47 kits are listed for this size too.

Sizing and fit

Downflow needs Lennox's 28B60 downflow kit, and horizontal left-hand discharge needs the horizontal drain pan moved. Match the air handler to your outdoor unit's tonnage.

Warranty and registration

HVAC USA is an authorized Lennox reseller, and everything we sell is new factory equipment. Your full Lennox warranty applies when a licensed, manufacturer-certified contractor installs your system and registers it within 60 days.

Shipping and help

This item ships free from our Kansas City warehouse to the lower 48 states and D.C., and so does the rest of your order, except to Washington, Oregon, and Idaho, where you pay the shipping rate shown at checkout. For Alaska, Hawaii, Puerto Rico, other U.S. territories, or an APO or FPO address, call or text us for a quote. Call (913) 364-0070, Monday to Friday, 9am to 5pm CST, and we'll help you confirm sizing and an AHRI-matched pairing before you order.